The operation of airlines and airports today focuses on achieving maximum efficiency to keep operating costs as low as possible while continuing to provide travelers with a safe and economical mode of travel. Arriving and departing aircraft must travel on the ground between landing and subsequent takeoff along runways and taxiways associated with an airport. It is acknowledged that many, if not most, delays in aircraft arrivals and departures result from delays in aircraft ground travel between landing and takeoff. It is additionally acknowledged that minimizing the time an aircraft spends sitting idle on the ground between taxi-in after landing and taxi-out prior to takeoff maximizes airline and airport savings. At many airports, space is constrained. Aircraft that are waiting to be towed or pushed back block the ramp area and taxiways, delaying the movement of incoming aircraft into the gate and blocking the transit of ground vehicles. It is desired to keep the time an aircraft spends on the ground at an airport between landing, arrival at and departure from a gate, and take-off to the minimum required to unload arriving passengers and cargo, service the aircraft, load departing passengers and cargo, and move the aircraft to and from the gate. Minimizing aircraft ground time not only reduces delays in airline flight schedules, but also increases the possibility that an airline can schedule additional flights, providing travelers with more options and improving airline profits.
The ground movement of landing aircraft is currently controlled by the aircraft's main engines until the aircraft reaches an arrival parking location. Upon departure, the aircraft is typically pushed away from its parking location by a tow vehicle to a more distant location where the engines can be started and used to move the aircraft to a runway for takeoff. The use of an aircraft's engines to move an aircraft at taxi speeds on the ground presents several challenges, including the dangers posed to persons and vehicles in the vicinity by jet blast and engine ingestion. Additionally, engine useful life may be shortened, not only by damage from foreign object debris, but also from sustained operation at the low speeds required for ground travel.
The use of vehicles that tow an aircraft a greater distance onto a runway than the distances traveled by currently available tugs or tow vehicles has been proposed. While this may diminish somewhat the use of an aircraft's engines during taxi, it does not necessarily shorten the time the aircraft spends on the ground and requires the maneuvering of additional vehicles and the personnel to attach and detach these vehicles from aircraft on already crowded runway and taxiway space.
Moving an aircraft on the ground during taxi by means other than the aircraft's main engines or turbines has been described in the art. U.S. Patent Publication No. US2009/0294577 to Rogues et al, for example, describes a device that enables an aircraft to move autonomously on the ground that employs a very specifically defined spiral drive gear to turn an aircraft wheel. The torque and speed of the wheel driver may be controlled according to parameters from other aircraft systems. Processing data relating to the operation of the device and making the required adjustments automatically, or even manually, to achieve optimized operation or performance is not suggested, however. In U.S. Pat. No. 7,445,178 and PCT Patent Publication No. WO2006/138267, McCoskey et al describe a powered nose aircraft wheel system useful in a method of taxiing an aircraft that can minimize the assistance needed from tugs and the aircraft engines. A precision guidance system including ground elements that interact with aircraft elements is disclosed for controlling movement of the aircraft on the ground during taxi. McCoskey et al, however, is completely silent with respect to whether the performance of this powered nose wheel could be optimized in any way to provide efficient aircraft ground movement and, if so, how that might be accomplished. U.S. Pat. No. 7,226,018 to Sullivan also describes a wheel motor useful in an aircraft landing gear wheel designed to provide motive force to an aircraft wheel when electric power is applied. Sullivan also fails to suggest any method for optimizing the performance and efficiency of the described wheel motor to move the aircraft effectively on the ground. U.S. Pat. Nos. 7,975,960 and 8,220,740, both to Cox et al and owned in common with the present application, describe a nose wheel control apparatus capable of driving a taxiing aircraft without the use of the aircraft main engines or tow vehicles. A method for automatically or manually optimizing the efficiency and performance of this apparatus is not suggested, however.
It would be highly desirable to be able to obtain and analyze information relating to the operation of an aircraft ground travel system and then make any required system adjustments automatically, or even manually, to optimize the efficiency and performance of aircraft ground travel. It would be desirable as well to utilize fully the benefits of a powered aircraft drive wheel capable of moving an aircraft efficiently during ground travel without engines or tow vehicles in optimizing ground travel system performance. The prior art has not provided a method for automatically or manually optimizing the performance and efficient operation of an aircraft ground travel system that employs one or more drive aircraft nose or main wheels powered by one or more onboard drivers to effectively move an aircraft independently on the ground.